Resilient block.



N. BUSBY.

RESILIENT BLOCK.

APPLICATION FILED mm. 0. 1000.

978,689, Patented Dec. 13,1910.

UNITED STATES rigrENrr OFFICE.

NAHUM JUDSON BUSBY, 0F BOSTON, MASSACHUSETTS.

RESILIENT BLOCK.

, ence marked thereon.

My invention relates to resilient blocks adapted for use in springs or tread surfaces.

and has for its object to provide an improved construction of the same that Wlll be comparatively inexpensive, will more readily retain their position because of their novel composition and will possess highly durable qualities.

Specifically described my improved s ring or tread surface is composed of an a mixture of an elastic material, such as rubber, felt, fiber or leather, and finely broken quartz, the composition possessing suflicient elasticity, and, by reason of the quartz, being more durable and possessing anti-slipping qualities.

In the accompanying drawing-Figure 1 is aperspective view of a circular block embodying my invention. Fig. 2 is a sectional view of the same. Fig. 3 is a perspective view of a square block. Fi .4 is a sectional view of a fiat thin block suitable for a tread surface.

t which is mixed aquantity of finely comminuted quartz, and in the composition of the same I so proportion the ingredients that the center of the block A is composed mainly of the uartz, the proportion thereof to the rubber iessening as the edge of the block is reached. The advantage of this construction is that, when the article is used as a resistance pad, where there is often as high as two thousand pounds ressure exerted thereon, the weakest point eing in the center of said pad, the blow will be more effectually resisted by the excess of quartz at that oint. I also prefer to form one surface of the look into a slightly projecting oval surface B, which may or may not be corrugated, and.

Specification of Letters Patent.

Application filed December 6, 1909.

Patented Dec. 13, 1910.

Serial No. 531.623.

which will cause the same to more firmly retain its adjusted position under pressure, and will also aid in resisting crushing strains on said block. By increasing the quantity-of quartz at the center I. not only reduce the wear on the block, but also increase its anti-slipping property.

A preferred method of manufacturing my improved article consists in first lacing in a suitable mold a layer of the elastic element, such as rubber, with which is mixed the quartz, as shown at 1 in Fig. 2. and which is apertured to receive the oval. surface B; then placing in the mold a layer 2 of rubber and quartz, the proportion of quartz being much greater than that in layer 1, and said layer projecting through the aperture in layer 1 to form the. oval surface B; and finally adding the layer 3, in which the proportion of quartz is substantially that of layer 1. The mold being now put in the vulcanizing press and its contents vulcanized, the block produced will be properly united.

My improved articles are peculiarly adapted for use to receive shaping or molding dies for pressing felt and similar material wherein an elastic resistance is necessary in order to prevent the fiber of the material being operated on from being broken. They are also well adapted for use as car springs, as treads for stairs, and for many other purposes wherein an elastic anti-slipping effect 18 desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A resilient block, composed of a mixture of elastic material and comminuted quartz, the proportion of quartz being relatlvely greater at the center and diminishing toward the edges of the block.

2. A resilient block, composed of a mixture of elastic material and eomminuted quartz, theproportion of quartz being relatlvely greater at the center and diminishing toward the edges thereof, and having its bearing surface formed into a projecting oval surface. I

NAHUM JUDSON BUSBY.

Witnesses:

1 NAHUM J. B'UsBY, Jr.,

HIBBARD S. B. C. BUsBY. 

